Chronic health problems play a fundamental role in individuals' retirement decisions and serve as the impetus for health-mandated disability exits. Despite the volume of empirical evidence on this association, almost nothing is known about the specific types of health conditions that prompt retirement and differentiate retirement from disability. Current understanding of the retirement-health relationship is based almost exclusively on global measures of health assessment such as "does health limit the amount or kind of work." Much less attention has been given to the nature of disease conditions that combine or progress to interfere with older workers' desire and ability to work. The proposed study is designed to redress this shortcoming. Our project has two primary aims. First, we propose to investigate how specific chronic health conditions, across a range of health domains, prompt retirement and disability exits. The analysis will focus on the effects of major fatal chronic diseases and other nonfatal diseases, conditions, impairments, functioning difficulties, and symptoms. Second, we propose to investigate how characteristics of the work environment accommodate or constrain the work ability of persons with chronic health conditions. Almost no research has evaluated how workers' retirement responses to specific chronic conditions differ according to the nature of their work. The theoretical framework takes into account the voluntary and involuntary responses (i.e., retirement and disability) that may be motivated by chronic health conditions. Workers with the same chronic conditions, but varying job demands, are presumed to face different obstacles to continued work activity. Some jobs will place few demands on workers with health problems, permitting them to continue working should they so desire. Other jobs will pose demands that exceed the individual's abilities to carry out the requisite tasks. As the job demands challenge and then exceed workers' abilities, we anticipate that workers' responses to chronic health problems will shift from retirement to disability. Panel data from three waves (covering four years) of the Health and Retirement Study will be used to estimate hazard models of the effects of chronic health conditions on the retirement and disability experiences of retirement-aged workers.